Modulating effects of interferon preparations on an antibody response in vitro

The effect of mouse interferon preparations on the primary in vitro antibody response of mouse spleen cells was studied. Concentrations of interferon greater than 8 units per ml significantly inhibited the antibody response while low concentrations of 0-08-0-8 units per ml could be shown to be mildly enhancing. Various treatments which affected the antiviral activity of the interferon preparations reduced the immunosuppressive activity to a similar extent. Interferon acts during the first few hours of a response but the effect is not apparent for at least 50 h. Interferon had no effect when added after 48 h. The kinetic data has been interpreted as demonstrating interferon-sensitive and interferon-resistant components of the in vitro response. The results from investigations of the polyclonal response to lipopolysaccharide support the view that interferon acts mainly on B cells alone, although effects on T-B interactions cannot be excluded.